package org.apache.maven.plugin;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Properties;

import org.apache.maven.plugin.descriptor.MojoDescriptor;
import org.apache.maven.plugin.descriptor.Parameter;
import org.codehaus.plexus.util.StringUtils;

public class PluginParameterException extends PluginConfigurationException {

  private final List<Parameter> parameters;

  private final MojoDescriptor mojo;

  public PluginParameterException(MojoDescriptor mojo, List<Parameter> parameters) {
    super(mojo.getPluginDescriptor(),
        "The parameters " + format(parameters) + " for goal " + mojo.getRoleHint() + " are missing or invalid");

    this.mojo = mojo;

    this.parameters = parameters;
  }

  private static String format(List<Parameter> parameters) {
    StringBuilder buffer = new StringBuilder(128);
    if (parameters != null) {
      for (Parameter parameter : parameters) {
        if (buffer.length() > 0) {
          buffer.append(", ");
        }
        buffer.append('\'').append(parameter.getName()).append('\'');
      }
    }
    return buffer.toString();
  }

  public MojoDescriptor getMojoDescriptor() {
    return mojo;
  }

  public List<Parameter> getParameters() {
    return parameters;
  }

  private static void decomposeParameterIntoUserInstructions(MojoDescriptor mojo, Parameter param,
      StringBuilder messageBuffer) {
    String expression = param.getExpression();

    if (param.isEditable()) {
      boolean isArray = param.getType().endsWith("[]");
      boolean isCollection = false;
      boolean isMap = false;
      boolean isProperties = false;
      if (!isArray) {
        try {
          // assuming Type is available in current ClassLoader
          isCollection = Collection.class.isAssignableFrom(Class.forName(param.getType()));
          isMap = Map.class.isAssignableFrom(Class.forName(param.getType()));
          isProperties = Properties.class.isAssignableFrom(Class.forName(param.getType()));
        } catch (ClassNotFoundException e) {
          // assume it is not assignable from Collection or Map
        }
      }

      messageBuffer.append("Inside the definition for plugin \'");
      messageBuffer.append(mojo.getPluginDescriptor().getArtifactId());
      messageBuffer.append("\', specify the following:\n\n<configuration>\n  ...\n");
      messageBuffer.append("  <").append(param.getName()).append('>');
      if (isArray || isCollection) {
        messageBuffer.append('\n');
        messageBuffer.append("    <item>");
      } else if (isProperties) {
        messageBuffer.append('\n');
        messageBuffer.append("    <property>\n");
        messageBuffer.append("      <name>KEY</name>\n");
        messageBuffer.append("      <value>");
      } else if (isMap) {
        messageBuffer.append('\n');
        messageBuffer.append("    <KEY>");
      }
      messageBuffer.append("VALUE");
      if (isArray || isCollection) {
        messageBuffer.append("</item>\n");
        messageBuffer.append("  ");
      } else if (isProperties) {
        messageBuffer.append("</value>\n");
        messageBuffer.append("    </property>\n");
        messageBuffer.append("  ");
      } else if (isMap) {
        messageBuffer.append("</KEY>\n");
        messageBuffer.append("  ");
      }
      messageBuffer.append("</").append(param.getName()).append(">\n");
      messageBuffer.append("</configuration>");

      String alias = param.getAlias();
      if (StringUtils.isNotEmpty(alias) && !alias.equals(param.getName())) {
        messageBuffer
            .append("\n\n-OR-\n\n<configuration>\n  ...\n  <" + alias + ">VALUE</" + alias + ">\n</configuration>\n");
      }
    }

    if (StringUtils.isEmpty(expression)) {
      messageBuffer.append(".");
    } else {
      if (param.isEditable()) {
        messageBuffer.append("\n\n-OR-\n\n");
      }

      // addParameterUsageInfo( expression, messageBuffer );
    }
  }

  public String buildDiagnosticMessage() {
    StringBuilder messageBuffer = new StringBuilder(256);

    List<Parameter> params = getParameters();
    MojoDescriptor mojo = getMojoDescriptor();

    messageBuffer.append("One or more required plugin parameters are invalid/missing for \'")
        .append(mojo.getPluginDescriptor().getGoalPrefix()).append(":").append(mojo.getGoal()).append("\'\n");

    int idx = 0;
    for (Iterator<Parameter> it = params.iterator(); it.hasNext(); idx++) {
      Parameter param = it.next();

      messageBuffer.append("\n[").append(idx).append("] ");

      decomposeParameterIntoUserInstructions(mojo, param, messageBuffer);

      messageBuffer.append("\n");
    }

    return messageBuffer.toString();
  }
}
